Hydraulic dumping-body hoist



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E. R. BARRETT HYDRAULIC DUMPING BODY H0151' Filed July 25, 19271 :s sheets-sheet 2 n y Eduard R, orre Patented Dec. 1 l, 1928.'

UNITED sTATns pAYrENT1-FFICE EDWARD R. BARRETT, -OIE DETROIT, MICIGAN, ASSIGNOR TO WOOD HYDRAULIC HOIST 8c BODY COMPANY, OF DETROTT, MICHIGAN, `A CORPORATION 0F MICHIGAN.

HYnRAULIc numerico-Boni Horse.

Application led July 25, 1927. Serial No. 208,074.

This invention relates to hydraulic dumping apparatus and is primarily concerned with a relatively simple, economically constructed and easily installed dumping apparatus adapted, in various sizes, to beiapplied to all 'ofthe different sizesof truck'sand dumping bodies appliedthereto. lVith the construction of the dumping hoist which I have invented, the design is such that when the tilting of the body is started at which time the greatest force has to be exerted to lift and tilt the body and its contents, the

distance through which the load'is moved is short, permitting the necessary multiplication of the power applied to the hydraulic piston in order to initiate the dumping movement; Vit-h the progress of the movement and the diminution of the lifting Vforce required for lifting and tilting the body the movement yis increased and the tilting of the body accelerated so that as the body approaches extreme tilted position its move-` ment is very much faster than it was at the beginning. vIt is an object and purpose of the present invention to provide mechanism capable of electingthe results' stated and 1n a simple and practical manner. l

A further object of thevfinvention is to 'construct a dumping hoist which` may be built and installed as a unit and which may be installed at various positions on the truck chassis frame'members, the unit hoist a's'sembly being merely laid on said members at the proper position and the holes bored for the bolting of the same in place, there being no necessity for boring different holes at different positions and properly correlating the same for the connection of separate parts of the hoist support. This greatly aids in the installation rendering the same very simple and easy. f

Many other obje-cts and purposes than those stated will appear as understanding of the invention is hadfrom the following description taken in connection with the accompanying drawings, in which, l

Fig. 1 is a longitudinal vertical section through `a dumping body and the vhoisting apparatus used therewith showing the same applied to a truck frame, the body being in normal horizontal position.

Fig. 2 vis asimilar view showing the body in partly tilted position.

Fig. 3 is' a like view showing the body tilted substantially to its extreme upper position Fig. is a plan view of the hoisting unitl and the chassis frame members on which it andthe frame and between the bodyand the hoisting .'unit' being shown in horizontal section, and 'l Fig. 5 is a .transverse vertical section -is mounted, the connections between the body through the truck frame body and hoisting unit, the plane-of the section being taken directly back of the cylinder of the unit and the View being that shown looking to the rear.

Like reference characters refer toA like parts in the. different figures of the drawings. The truck chassis frame includes the usual ,channels 1 comprising the side frame members over which the body 2 is mounted. The

body preferably is of sheet steel carried on parallel channel sills 3 which lie above and in the same plane with the frame members 1.

Plates l riveted or otherwise permanently secured to the sills 3 adjacent their rear ends extend downwardly along the sides of the truck Jframe members land are pivotally connected thereto at their lower ends as indi cated in dotted lines at 5. Beams 6 of wood are fastened-to the upper flanges of the vframe members 1 in front of where the hoist unit is mounted, the front end portions of the sills 3 resting on the beams G when the body is in horizontal position. f

In the constructionvof the hoisting unit, two parallel spaced apart angle bars 7 and 8 are provided which, when installed on the truck, lie transversely above and between the truck frame members 1 and are rigidly bolted vto vthe upper flanges thereof. The bar 8 is located in front of the bar 7 and between the same two racks 9 of the form shown are placed and permanently secured, one of said racks being located .a short distance inward of each of the frame'members 1. The racks 9 at their upper sides 'are provided with y spaced apart teeth 10 which extend upwardly from the upper sides of the racks. The racks curve slightly upward from their front to their rear ends as best shown in Fig. 1.

At the rear end of each rack 9 an integral upwardly and inwardly'extending post 11 curved in a forward direction at its upper inder 14 and are Connected with said front end in any suitable'manner serving as a support for the front end of the cylinder' which extends to the rear lying. between the diagonal supporting and bi'ace bars l2. The

cylinder has the usual valveless piston therein, and is illed with liquid, usually oil, which is pumped into the front end through the inlet pipe 15 while the oil back of the piston is returned to the pump through the outlet pipe 16 connected tothe rear end oiI indcr. (See Fig. 1.) 4

A piston rod 17 is connected with the piston in the cylinder and passes rearwardly through f the rear end of said cylinder. At the rear end of the piston rod a cross head is secured consisting of a sleeve 18 fastened to the piston rod and attached to a transverse shaft 19 which passes underneath the bars 12. The

shaft 19 at its ends'isrotatably mounted in ,two segments-20, one at each end of the shaft, each of which is formed with a plurality of spaced apart projecting teeth 21, 22, 23, 24 and 25. 'The number of teeth on the segments 20 and the number of teeth on the racks 9 maybe varied but in every instance the distance from `the center of the shaft 19 to the pitch line pfthe successive teeth 21 to 25 inclusive increases with each succeeding' tooth. That is, the pitch radius of the tooth 21 is shorter'than that o f any lof the others;

and of the tooth 25 is longer than any of the others and there is a progressive increase in pitch radiuswitheach tooth from the tooth 21 to the tooth 25. v

lFrom each of the segments 20 an arm 26 extends which when the body is in lower horizontal position is located vertically as shown in Fig. 1. A link 27'is pivotally connected to the end of each of the armsA 26 and extends vertically therefrom so that the upper ends ofthe links lie closely adjacent to the bottom ofthe body 2. A shaft 28 passes through the upper ends of the links and is mounted at its ends in bearing plates 29 permanently secured to the inner sides of the channels 3 which form the supporting sills of the body.

When oil is pumped through the pipe 15 into the cylinder 14 the piston and the piston rod 17 connected therewith' move to the rear with a consequent bodily movement of the shaft 19 to the rear: This bodily movement The bars entend over the ot the shaft 19 causes the segments 20 toturn and roll back on the racks 9. During the initial part of this movement the upward movement ot the ends of the arms 26 is in ratio to the sine ot the angle made by the arm .26 to the vertical. At the initiation o'f the movement ,the body and the load car-` ried thereby 4are in the lower horizontal position and the force required to overcome the inertia of the body and load and lift the same is very great; and this is compensated for by the fact that the power applied to the piston in the cylinder moves through a relatively long distance compared to the vertical lift Jf the body `when the tilting movement is started so4 that the pressure on the piston does not have to be unduly excessive.- With the` 'progress of movement the upward movement oi the ends of the arms 26 increases, -wlule .the segments 20 roll to the rear turning about a progressively decreasing axis due to the decreasing pitch radius of the successive teeth increasing tilting movement of the body -the distance through4 which the power. has to work progressively decreases sov that the tilt- I ing oi the body starts slowly andconstantlyV accelerates until the extreme tilted position is reached, maintaining the Working ressure of oil against the piston substantia ly constant.

With the upward tilting movement of the body it is evident that the load normally shifts to the rear and it is further evident that even if the load does not thus shift the movementcf the center of gravityof the load and bodyvertically decreases for a given tilting movement as the body is turned away from lthe horizontal so that less power is required to tilt the bod and its contents during the later stages o movement than at the beginning. It is evident that with this construction a substantial balanceis attained whereby substantially the same pressure on the piston throughout the entiremovement may be maintained, the differences in the acceleration of the body in its movements being such that the pressure applied to the piston remains substantially constant. This is a very desirable quality in hoistsof this character insuring that destructive .pressure and strains willibe eliminated and no pressure or strain produced which will'break or distort any partof the mechanismthereby insuring a long working life for thesame.

It is further evident that theaunit construction of thehoisting apparnltnsis a feai ture of great valuefinlthematter of installing the same on trucks.i It is necessary 'merely iin v l to attach the bearing plates Installationdrilling holes through the flanges of the truck frame members 1 to correspond with i the holes made through the anglebars 7 and 8, insert and connect the bolts used for fastening the same in place, and then bore the holes in the webs ofthe sills 3 at the proper place is thus made very simple requiring little or no The construction of hoist described has proven very satisfactory. It may be designed in different sizes for large or small truck and body capacities. There are few parts fall-of which are easily produced and assembled.-

The invention is dened in the appended claims and is to be considered comprehensive of all forms of structure coming within their scope.

I cla-im: f

1. In combination with a truck frame having spaced apart sides,-a pair of racks mounted on said frame, one near each side thereof, gear segments to traverse each lrack from front to rear and vice versa, each of said segments having an arm extending therefrom Iin a downward direction when the segments are in forward position, a'l shaft disposed between the segments on which the same have a4 rotatable mount, a dumping bodyv tiltably mounted on the truck frame, links connecting the ends of said arms with the body and hydraulic means for movingr said shaft rearwardly to thereby cause the segments to traverse the racks from front to rear. y. 2. In combination withI a truck frame having spaced apart frame members, a pair of racks mounted on said truck frame one adjacent to each side thereof, gear segments vmounted above. said racks to traverse the same, each of said segments having an arm extending therefrom, a shaft disposed 4be-` tween the segments on whlch said segments are rotatably mounted, a dumping body :tiilit-- ably mounted on the truck frame, links oon-v necting the ends of said arms with .the body at theunder side thereof and means for moi7` ing said shaft` rearwardly to cause the segments to move over the racks to the rear.

, y3. In combination a truck frame, aplu-` rality of racks mounted on said truck .frame iinparallel -relation to each other and in ver- A tical planes parallel tothe side of theframe, l a gear segment mounted on and above each rack, eachl of said segments having a plupitch radius from one terminal tooth to the other in each segment, 'a shaft disposed between the segments on which the same are rotatably mounted, means for movin(y said shaft to the rear, a dumping body t1l-ta`bl57 m0`unted on the truck frame and ,connections between said body and the gear segments for tilting the body upwardly and to the rear -when said shaft is moved rearwardly.

4. In con'ibina'tion with a truck frame, cross bars extending between the sides of the frame and spaced from each other, a plurality of racks-carried by said cross bars, a gear segvment mounted on and above each rack, a shaft disposed between said segments on which the same are rotatably mounted, an arm extend'- ing fromeach segment, a dumping body tiltably mounted on the truck frame, links connecting the ends of said arms withithe body 4`at its under side, a hydraulic cylinder encloskandieach 'ofsaid segments including a plurality of teethhaving a progressively increas- 'ing pitchradius from one terminal tooth to theother in a segment, the `tooth havingthe longest pitchl radius being engaged with the rack when the body is in lower horizontal position. fV 6. In icombination with a truck frame having spaced apart side frame members, a pair of spaced apart cross bars lying between and above the side frame members of the truck fra-me land permanently secured thereto, a plurality of racks carried by and between said cross bars, a gear segment mounted on and above each rack, ash'aft extending between the segments ron. which the same are .rotatably moun-ted, eachof said segments having an arm extending therefrom at a side of the axis 'of the .shaft opposite the side to which the segment is located, said arms extending substantially vertically downward in the forward position of said segments on the racks, a body tiltably mounted adjacent its rear portion on the rear end of the truck frame to tilt about a horizontal axis, links pivotally conncting thefree ends of said arms with the `connected vtta-.said cross bars, each rackl member' at its rear end having an up wardly extending post, a gear segment mounted to traverse each rack and formed with an varm extendingtherefrom, a shaft extending betweenxsaid segments on which the' same .are rotatably mounted, a link atrality of teeth of progressively increasingtached to the end of each arm, brace bars connected at their rearends to the upward ends of 'said posts and extending forwardly over-said shaft and converging toward their -front ends, brackets connecting the frontv crossbar and said brace barsa hydraulic cylinder located between the front portions ciated with said frame, a gear segment mounted to traverse said rack, a link eccentrically connected to said gear segment and also-connected to said body, and means for traversing said gear segment on said rack.

9. In combination with a truck framehaving a dumping body tiltably mounted thereon, a hoisting devicecomprising a rack associated With said frame, a gear segment mounted to traverse said rack, saidgear segment having a progressively increased pitch radius from one terminal to the other, means connected with said gear segment eecentriewith its axis and associated with said body for tilting said body by movement of said gear segment, and means for causing the gear segment to traverse the rack.

10. In combination with a truck frame having a dumping body tiltably mounted thereon, a hoisting device comprising a rack associated Withsaid frame, a gear segment mounted to traverse said rack, said gear segment having a progressively increased pitch radius from one terminal to the other, means connected With'said gear segment eccentric with its axis in proximity to its greatest pitch diameter and associated With'said body for tendingover and in proximity With said shaft, and means for exerting a thrust upon said shaft, said means boing connected-to and supported by said brace bars at their ends opposite their connections with said racks, and means associated with said gear segments and adapted to be attached to the tilting body of a truck for hoisting the same.

l2. A hoistino unit comprising, cross members adapted to be mounted upon the frame of a truck, racks mounted on said cross mem-` bers, a gear segment associated with and adapted to traverse each rack, a shaft extending between said gear segments, a brace bar attached to each rack and extending over and in proximity with said shaft, 'a hydraulic cylinder supported byl said brace bars, a piston in said cylinder having a piston rod connected to said shaft, and means associated with said gear segments and adapted to be attached to the tilting body of a truck for4 hoisting the same.

In testimony whereof I affix my signature.

EDVARD R. BARRETT. 

